Process of and apparatus for desiccating substances



(-No Model.) 3 Sheets-Sheet 1.

"L. J. GADWELL'. "Process of and Apparatus for Desiccating Substances.

No. 239,722. Patented April 5,1881.

MPETERS. PHOTO-UTHUGRAPHER, WASHINGTON, I? C.

(,No Model.)

' w 3 Sheets-Sheet 2 L. J. GADWELL. Process of and Apparatus forDesiccating Substances. No. 239,722; Pa'tented'April 5,1881.

N-PEI'ERS, FNOTO-LITNOGRAPHER. WASHINGIDN, D. 6'

(No Model.) L- J. OADWELL. 3 Shee ts-She'et 3.

Process of and Apparatus for Desicc'ating Substances. No. 239,722.Patented April 5,1881.

WITNESS 525;

N. PETERS, PHOTaLITHOGRAPr-IER. WASHINGTON. D 04 UNITED STATES PATENTOFFICE.

LYDIA J. GADWELL, OF CHICAGO, ILLINOIS.

PROCESS OF AND APPARATUS FOR DESICCATING SUBSTANCES.

SPECIFICATION forming part of Letters Patent No. 239,722, dated April 5,1881.

Application filed December 3, 1880.

To alt whom it may concern:

Be it known that I, LYDIA J. UADWELL, of

Chicago, State ofIllinois, have invented certain thoroughly desiccateeggs, glue, and other liquid materials of such nature as are or willbecome viscid or decrease in tenuity when partially dried, and reducethem to such a hard condition as will enable them to be pulverized orbroken; and this 1' effect by the method of treatment and the new andimproved apparatus hereinafter described, and illustrated in theaccompanying drawings, in which- Figure 1 shows an endless belt and itsappliances within the vertical drying-well by a vertical section of thelatter. It also shows an adjacent supplemental drying apparatus incentral vertlcal section, and the furnace from which heated air issupplied to both the well and the supplemental drying-chamber. Fig. 2 isa horizontal section of a group of two vertical drying-wells and acontiguous supplemental drying-chamber in the line 2 2 of Fig. 1. Fig. 3is a perspective view of the feedingpan detached and Fig. 4. shows agroup of two vertical drying-wells, one being in elevation and the otherin vertical section. In the latter is presented a front view of theendless belt and other parts related thereto.

A is a tall shaft or well, in appearance resemblinga large chimney, butpreferably closed at the top, and constructed of wood, (or otherwise,)to retain heat.

B is a belt or band, of canvas or,other similar or suitable material,hung within the well A from the loose drum D, situated near the top ofthe w ell, and propelled from the larger drum D, located near the bottomof the well, being driven by any suitable power or mechanism. (Not hereshown.) For the purpose of tightening the belt B, when required, theshaft 61 of the drum D is mounted in movable bearings L L, arranged toslide up and down be tween the guides L L, and provided with (No model.)

threaded rods L which depend therefrom through cross-pieces or bracket-sL beneath which wheel-nuts L serve to draw the drum D forcibly downward,and thus to give the desired tension to the belt. At one end of the drumthe shaft d protrudes through a vertical slot in the drying-well, and isprovided with a driving-pulley, P. The belt is slowly driven in thedirection of the arrows b b.

F is a pan, preferably semi cylindric in shape, to conform with the drumD, intended to contain a quantity of the substance to be dried, andadapted to be raised and lowered to feed said substance periodically, ifdesired, upon the belt B. For the purpose of raising and lowering saidpan it is suspended by the chains F from the Windlass F, which issupported by the walls of the drying-well A, and is provided with anexternal crank, f, whereby it may be operated at will. T is a tank,intended to contain a mass of the substance to be dried, and desirablylocated above the level of the pan F. It is provided with the pipe T,which dlscharges into said pan, and which has the valve t, by which thesupply of material from the tank '1 to the pan F may be controlled.

J is a hot-air furnace, suitably located with reference to thedrying-well A, and provided with a flue, J, which discharges heated airinto the well, as indicated. I prefer to admit the air at that side ofthe well at which the belt B descends, and to discharge themoisture-burdened air from the well at the oppositeside, near thebottom, as indicated at J An important economic advantage is realizedfrom having the drying-well closed at the top and provided with inletand outlet at the bottom, as shown, in that the drier and hotter airinevitably rises to the top of the well over the descending portion ofthe belt, and settles and escapes only as it becomesladen with moisturepassing over the ascending portion of the belt. There is, therefore, noescape of hot air unutilized, and, on the other hand, the escape of airis insured as fast as it does its work,

while the moistureladen air is not carried over the dry portion ofmaterial. The wellmay, of

course, be operated, though less effectively and economically, byallowing the heated air to escape at the top or elsewhere.

E is a roller, hung by the arms e from the i I y cross-bar e in positionto bear transversely against the belt B, as clearly seen in Fig. 1. Theobject of this device is to spread or break up and disintegrate thesubstance on the belt while being dried, in order that new surfaces ofsuch substance maybe successively exposed to the drying air, and alsoin'order to facilitate or induce a granulation or crystallization of thesubstance, if it be such as is capable of this effect. Several rollers Emay be employed, if desired, and located-to bear at different points onthe belt, by which the effect sought will be practically continuous. Bymeans of the external arm or lever, e, the roller E may be lifted-awayfrom the belt, and it may be held away by the looped cord 0. Any othersuitable carrier may be used for the purpose.

S represents a scraper, of the full width of the belt B, secured to therocking shafts, and adapted to be borne by the lever-arm S against thedescending surface of the belt, as shown in full lines in Fig. 1. Thisscraper is for the purpose of removing the dried or partiallydriedsubstance from the belt. While said scraper may be made of a singlepiece of metal, it preferably consists of a number of blades arrangedside by side to extend across the belt, as indicated in Fig. 4. In thiscase each section may be given an oblique or curved form at itssharpened end to obtain a shearing action, and thus to operate moreeasily. The scraper is sharpened by being beveled on its under face,that it may not cut the belt while in operation. Said scraper, whenborne in an inclined position against the belt B, also serves as a chuteto conduct the detached substance away from the belt, and in thischaracter is prolonged by the broad apron or chute s, also secured tothe shaft 8, so as to direct the substance detached into the spout Sleading out of the well. If it is not desired to use the scrapercontinuously it may by these devices be swung, together with the apron8, into the vertical position shown in dotted lines of Fig. 1, so as toafford no appreciable obstruction to the upward passage of air in frontof the belt. Said scraper may obviously be hinged to the well-wall atthe mouth of the spout and turn up against the well when not in use; or,if intended for constant use, it may be fixed in the inclined positionshown. Any suitable appliance may be used for adjusting the scraper.Opposite the point at which the scraper bears against the belt islocated a large loose drum, D which supports the belt in opposition tothe pressure of the scraper. Any other suitable form of support may beemployed instead of the drum D and, less desirably, such drum or supportmay be movable and adapted to deflect the belt outward against thescraper set a short distance from the belt when the latter hangs free.

As the apparatus so far generally described is complete in itself forcertain important purposes of my invention, and as it embraces the moredistinctively novel mechanical features of said invention, I nextdescribe its operation more in detail, illustrating my improved processin connection with one use to which it may be applied-namely, thedesiccation of eggs. For this purpose I will suppose the ultimatedesiccated egg product to be that set forth and patented in LettersPatent of the United States No. 184,479, consisting of granular powdercomposed of both the whites and yelks of the egg and a suitable quantityof sugar for their preservation. To make this product the yelks andwhites of eggs are thoroughly broken up together and intimately mixedwith a due quantity of sugar, forming what is called egg-batter. Thisbatter is held in a mass in the tank T. From this tank the pan F issupplied through the pipe T, and

the batter is fed from the pan to the outer sur-' face of the movingbelt B. If the feeding is desired to be intermittent, it will beaccomplished by raising the pan through the agency of the Windlass F, asdescribed, and holding it in the elevated position until a sufficientquantity adheres to the belt-surface, when the pan will be lowered untila new or further supply is wanted on the belt. Such new or furthersupply of batter to the belt-surface may be required and applied afterthat first applied has become partially dried and set, so as to assistin retaining an additional quantity, or after that first applied hasbeen dried and removed. If, as may be the case in the use of a belt ofsufficient length and of an adequate heat, the drying is completedin asingle revolution of the belt, the application of the batter may be madecontinuous, and this will be done by holding the pan in the raisedposition and continuing the supply thereto from the tank T. Ordinarily,after one application of batter to the belt, covering its entiresurface, the supply will be discontinued and the belt will be revolvedseveral times before the substance thereon will be dry enough to beremoved. While the belt is thus revolved hot air is admitted from thefurnace-flue J, and discharged as it becomes laden with moisture at theoutlet J With the outlet located as shown the air-current will generallybe in the direction of the arrows at but as the belt is narrower thanthe well said belt is obviously exposed on all sides to the heated air.

During the earlier part of the drying process, and while the latter isyet in a more fluid state, said batter is disposed to flow on the belt,wherefore I have made the lower drum,

D, larger than the upper one, D, or have thrown the lower. end of thebelt out beyond the upper. This feature of construction lessens thetendency of the batter to flow, and in case it does flow causes anyportion of the batter that may be detached to drop back on the belt at alower point. It is most important that the descending side of theband'be thus inclined, as the thickness of the nearly dry material ismade uniform and the presence of undried lumps avoided.

The roller E, which bears against the belt B and is thereby rotated,plainly operates to respread the mass on said belt at every revolutionthereof, and thus to crush the lumps above referred to, and to maintainan even distribution of the egg substance on the belt, favorable to itsuniform drying throughout. In doing this the drying process is itselfmaterially hastened, since the roller necessarily disintegrates, breaksup, and stirs the mass being dried, and thus exposes continually newsurfaces of such mass to the action of the heated air. In the laterstages of the drying process, as performed on the belt, said roller alsocontributes to another and very important effectnamely, the granulationor-crystallization of thesubstance being dried, to which end it operatesby the stirringaction referred to, which has its analogy in theoperation or stirring in the manufacture of sugar from sirup. In thecase of egg substance, moreover, whether composed of the whites andyelks together, or of either separately, or of either or both combinedwith saccharine matter, there is a tendency to rapid expansion of thealbuminous portion or cells, and thus to their escape and loss in theform of fine dust or flakes. working, and spreading of the mass by theroller E or equivalent device, as the drying process goes forward, serveto preventthis undue expansion, unequal evaporation, and separa albumenthus stirred in while being dried seems, in connection with the sugar,to take a crystalline form, favorable to its ultimate reduction topowder. It several revolutions of the belt are made to complete thedrying process the scraper S is held during such process in averticalposition away from the belt, as stated, and as indicated in dottedlines. When the egg substance is sufliciently dried to be removed thescraper is pressed against the belt by means of the lever S, or by meansof a spring, or otherwise. The loose drum or roller D meets thep'ressureof the scraper and prevents the belt from being unduly deflected andstretched, and also insures a more perfect action of the scraper. Beingarranged as shown, the scraper S forms an inclined chute, prolonged bythe metal apron s, which serves to direct the detached egg substanceinto the spout S by which said substance is conveyed out of the well A.As a result of this process the egg or other material is usually takenfrom the belt in such a state ot'dryness as to be broken up into coarsefragments by the action of the scraper in removing it. In this broken orfragmentary condition it is fit to be subjected, if necessary, tofurther and final drying preparatory to being ground and packed formarket.

For the purpose of the final drying I have provided the large inclosedsquare chamber 1, Figs. 1 and 2, upheld over the furnace J by the posts1 In this chamber are placed one or more large circular drying-pans, GrG. Fig.

Frequent mixing,

1 shows two such pans arranged one above the other. The upper may, ifpreferred, have a bottom of perforated metal, perforations beingindicated at g g. It also has a large central aperture, g, by which thesubstance being dried passes to the lower pan, 'G. The latter has adischargeopening. G at its circumference, which is here shown to leadout of the chamber 1, and may lead directly to the grinding-mill. (Notshown.) The spout S discharges into the upper pan, G, at its periphery.Through the center ofthe pans G and G rises a shaft, H adapted to berotated through the bevel-gear h, or otherwise, and provided with arms HH,respectively hearing wings h h, which sweep about in the drying-pansin the direction of the arrows d. The wings hh are set obliquelyon thearms, to which they are secured, and serve to stirthe substance being(lried,and also, by their obliquity, to gradually carry the same to thedischarging-apertures of the several pans. Thus the wings h on arm Hcarry the substance received at the periphery of the upper pan, G,inward to the aperture g, and the wings h carry it outward in the lowerpan,'G, to the discharge G Hot air is admitted to the chamber I from thefurnace J through the tlue J and finds escape from said chamber at 1preferably provided with a sliding door or register, I, to regulate theoutflow.

There is nothing essentially new in the construction of the supplementaldrying apparatus itself, as described; but it is new in the combinationshown, and it moreover illustrates a step in my process which is alsonew.

In the foregoing description of my improved process as performed by theapparatus herein set forth, I have supposed the substance operated uponto be an egg-batter composed of the whites and yelks of eggs and aquantity of sugar. I wish it to be understood that I am not limited asto my process to the treatment of this particular egg-batter, as saidprocess is equally applicable to the desiccation of the whites andyelks, either together or separately, and to either or both of thesewith or without saccharine or other substance; nor do I wish to belimited, either as to my process or as to the use of my machine, to thedesiccation of eggs, since said apparatus and process are obviouslyequally applicable to the drying of other than egg substances that maybe made to adhere to a belt. I further do not wish to be limited to thevertical arrangement of the well A with a belt of cloth or similarmaterial than with a metal belt, and the substance may therefore bebrought to a condition on the belt in which it is adapted to break up orseparate in fragments in the 'act of removal, whereby it is betterfitted for the supplemental drying.

While I have referred to a belt or band as being used in connection withthe'device for disintegrating; the film, such device may be used withany other film-carrier as, for instance, a roller or plate; and althoughI have referred to and prefer a roller for breaking up the films, otherdevices may be used with like effectas, for instance, a series ofvibrating plates or blades brought against the film and moved awaytherefrom as it is moved by the carrier.

While for many purposes it is desirable to use heated air, for otherpurposes the air may be cold. A strong blast is sometimes desirable. Atother times the. desiccation may be effected without any artificialheating or moving of the air, and in some instances the products ofcombustion may be taken directly from the furnace to and through thedryingchamber.

Other means than those described may be used for depositing the liquidmaterial upon the surface of the carrier. For instance, when the belt ishorizontal, or nearly so,it may pass beneath a hopper, from whichthematerial falls upon the belt.

I am aware that in treating paper-pulp and other mixtures the same havebeen dried by simultaneously heating and agitating or stirring.This,however,is,notmyinvention,which requires that before anydisintegration the substance be in a semi-hard or viscid state, and thenworked or agitated, while drying, until reduced to the form of thin hardparticles or powder.

I claim 1. The within described improvement in treating eggs and otherliquid or semi-liquid substance, the same consisting in first treatingthe substance until it is in a viscid, semihardened condition, and thenmechanically (11sintegrating the same while drying, substantially as setforth.

2. In thedesiccationof eggs and other liquid or semi-liquid substance,first subjecting such substance, while upon a carrying-surface, to theaction of air or gas until it is in a viscid or partially-hardenedcondition, and then completing the hardening and breaking up or reduction to powder by working or disintegrating the same, while drying,by contact with one or more blocks or blades, whereby the film is brokenand disintegration is effected.

3. The combination, in a desiccating apparatus, of a-band, means fordepositing on the same a film of the material to be dried, applianceswhereby said film is subjected to the action of dryingor hardeninggases, and means whereby the film upon the band is stirred and brokenafter artial hardening, and prior to removal, substantially as Sll]forth.

4:. The combination, in a desiccating apparatus, of the shaft or casing,heating or drying appliances, traveling band B, roller E or itsequivalent, and roller-carrier, constructed to permit the roller to bethrown into or out of contact with the band, substantially as set forth.

5. The combination, with the casing, heating or drying appliances, andendless belt B, of the scraper S, arranged to bear on the moving surfaceof the belt, and a support arranged to oppose the pressure of thescraper, substantially as set forth.

. In testimony that I claim the foregoing as my invention 1 afiix mysignature in presence of two witnesses.

LYDIA J. OADWVELL.

Witnesses:

M. E. DAYTON, HERBERT VANDYKE.

